Adjustable seat



FIG. 1 is a perspective view of an adjustable seat, showing our design;

FIG. 2 is a bottom plan view;

FIG. 3 is a side perspective view;

FIG. 4 is a rear perspective view; and

FIG. 5 is a side perspective view showing the adjustable seat, in an alternate position. 

The ornamental design of an adjustable seat, as shown and described. 